Hydrothermal synthesis and structural studies of a new coordination polymer of lanthanum(Ⅲ) with benzene-1,2,4,5-tetracarboxylic acid and 4,4′-bipyridine

摘要

A new lanthanum complex formulated as {(bpyH2) [La(btc)(H2O) 4(NO3) ]·2H2O}n(1) (btcH4=benzene-1,2,4,5-tetracarboxylic acid;bpy=4,4′-bipyridine) was hydrothermally synthesized. The complex was characterized by FT-IR spectroscopy,elemental analysis and X-ray diffraction. X-ray crystal structural analysis revealed that the compound belonged to the monoclinic space group C2/c with cell parameters a= 1.42806(7) nm,b=1.10258(5) nm,c=1.60333(8) nm and β=101.9400(10) °. The complex was polymeric with LaIII atoms linked by four O atoms from two carboxylate groups of one benzene-1,2,4,5-tetracarboxylate. The LaIII atom was ten coordinated in a distorted tetracapped trigonal prism. In the crystal structure,a wide range of noncovalent interactions consisting of hydrogen bonding(of the types of O-H···O,N-H···O and C-H···O) and ion pairing interactions connected the various components into a supramolecular structure.